Ecological security assessment and ecological management zoning based on ecosystem services in the West Liao River Basin

Ecological security (ES) can express the health and integrity of regional ecosystems; hence, a better understanding of regional ES levels and their influencing factors can help to specify sustainable ecological management policies. Levels of ES in the West Liao River Basin were computed for the years of 2000 to 2020 at both the grid and county scale by using the pressure-state-response model, with ecosystem services also included in the assessment system. From 2000 to 2020, the area of both the forests and grasslands increased, due to the Grain for Green Project, which augmented net primary productivity (NPP), an ecosystem production service, and enhanced the overall habitat quality of the basin and promoted improvements to the regional ecological environment. The ES levels in most areas of the West Liao River Basin were improved over time, in that >90% of its area was above the middle level in 2020. The coordinates of "very insecure" moved to the basin's southeast, while "very secure" moved to its northwest, which indicated serious ES problems in the southeast of the basin. When compared with the most economically developed areas or remote areas having societal progress and human activities, generally the moderately developed areas have better ES levels. Further, human factors are more important to ES than natural factors, though all driving factors had enhanced impacts on the change in ES via their interactive effects. By determining the ES levels of the basin, four ecological management zones were then derived for it. We identified the main environmental problems in each ecological management zones and put forward the corresponding management measures, which would make the results more useful for supporting resource management and ecological protection of ecologically fragile areas in the agriculture and pasture interlaced landscape of northern China.